Chlorinated hydrocarbons and improved rubber sealant compositions incorporating same

Abstract

An improved chlorinated hydrocarbon is provided which is uniquely compatible with polysulfide rubber sealant formulations when incorporated as a plasticizer therein. Certain paraffins or alpha-olefins and blends thereof when chlorinated to selected final chlorine contents are compatible with polysulfide rubber sealant formulations while still maintaining the necessary low viscosity and volatility when incorporated as a plasticizer therein. The improved plasticizers are not subject to significant heat loss. Modified polysulfide rubber sealant formulations are disclosed which incorporate as a plasticizer the improved chlorinated hydrocarbon, and which are useful as glass or window sealants, particularly as glass or window sealants between the panes of a thermal pane or multi-pane insulating window structure. The improved plasticizers are non-fogging in polysulfide rubber formulations and are not subject to significant heat loss.

Description

EXAMPLE I

For Runs No. 1-25, a variety of hydrocarbon feeds were provided to be chlorinated to various levels of chlorine content by the process as described above. In most cases, about 300-400 grams of alpha-olefin or normal paraffin was charged to a glass reactor vessel equipped with a temperature sensing means, sparger, sealed agitator and condensor. The reactions were carried out under ambient lighting conditions.

Each feed was heated with agitation to 85.degree. C. and chlorine bubbled into the mixture. For the alpha-olefins, reaction was immediate and the temperature was allowed to surge to 100.degree.-110.degree. C. For the normal paraffin reaction, chlorine was added at 85.degree. C. with heating continually applied until this reaction mixture reached 95.degree. C.-105.degree. C. (this will vary as function of the chain length of the feed hydrocarbon) at which point the reaction started. Chlorine addition was continued while maintaining temperature generally at 110.degree..+-.10.degree. C. until the required amount of chlorine had been added. Each product was then cooled and air blown for about 1/2 hour while maintaining the temperature in the range of 70.degree.-95.degree. C. The product was neutralized in a conventional manner and air blowing continued for 15 additional minutes at the above temperatures. The products were all stabilized with a conventional stabilizer.

The chlorinated hydrocarbons obtained are described below in Table I.

For run 3, which is within the scope of this invention, the chlorination procedure of U.S. Pat. No. 3,896,183 was followed. Runs 1-2 and 4-7 are also within the scope of this invention.

In runs 8-25, various plasticizers were selected for comparison purposes. Those samples are described below in Table I.

The hydrocarbon feed stream employed in runs 1,2 and 3 essentially of a C.sub.15 normal paraffin. The feed stream included about 3-5 weight percent C.sub.14 normal paraffin, about 13 weight percent C.sub.16 normal paraffin, about 3 weight percent C.sub.17-18 normal paraffin and about 0.1 weight percent of paraffins below C.sub.14.

TABLE I __________________________________________________________________________ Chlorinated Liquid Hydrocarbon and Comparison Samples (Estimated Heat Loss- Actual Weight Weight Per- Viscosity- weight percent Run Percent Chlor- cent Chlor- Centipoises Fog after 24 Compati- No. Nature of Feed ine Content ine Content) at 25.degree. C. Test.sup.2 at 105.degree. C. bility __________________________________________________________________________ 1 C.sub.15 normal paraffin 54.1 6200 passed(4) -0.14 Not available 2 C.sub.15 normal paraffin 56.9 15,620 passed(4) -0.18 Not available 2a Blend (a)-42% C.sub.20 -olefin -- 52.8 16,320 passed(1) -0.40 Not 36% C.sub.22 .alpha.-olefin and available 7% C.sub.24 .alpha.-olefin (chlorinated to 51.9 weight percent) and (b) 15% C.sub.12 n-paraffin (chlorinated to 58%) 3 C.sub.15 normal paraffin 53.8.sup.6 4860.sup.5 passed(1) -0.24 clear.sup.4 4 C.sub.18 normal paraffin 50.8 50.5 4490 passed(4) -0.06 clear.sup.4 5 C.sub.22 normal paraffin 50.5 50.4 21,400 passed(4) -0.06 clear.sup.4 6 blend (a) 25% C.sub.14 n- -- 54.2 16,120 passed(2) -0.11 clear.sup.4 paraffin and 25% C.sub.14 .alpha.-olefin, (blended & chlorinated to 57.9 weight percent chlorine); and (b) 50% C.sub.22 n-paraffin (chlor- inated to 50.5 weight percent) 7 blend-50% C.sub.14 n- 57.8 57.8 11,573 passed(1) -0.12 clear.sup.4 paraffin; 50% C.sub.14 .alpha.-olefin 8 C.sub.14 normal paraffin.sup.1 49.6 49.4 404 failed -0.95 clear.sup.4 9 C.sub.14 normal paraffin.sup.1 52.6 52.4 976 failed -0.56 clear.sup.4 10 C.sub.14 alpha-olefin.sup.1 52.6 52.4 824 failed -0.57 clear.sup.4 11 C.sub.14 alpha-olefin.sup.1 63.2 63.5 397,500 passed(4) -0.05 clear.sup.4 12 C.sub.14 normal paraffin.sup.1 63.4 63.3 617,000 passed(4) -0.05 clear.sup.4 13 blend-50% C.sub.12 n- 52.8 52.5 243 failed -4.54 clear.sup.4 paraffin; 50% C.sub.12 .alpha. -olefin.sup.1 15 C.sub.12 alpha-olefin.sup.1 57.9 57.8 1770 failed -1.03 clear.sup.4 16 blend-50% C.sub.12 n- 63.2 63.1 30,240 failed -0.29 clear.sup.4 paraffin; 50% C.sub.12 .alpha.-olefin.sup.1 17 C.sub.12 alpha-olefin.sup.1 59.1 58.7 2755 failed -0.57 clear.sup.4 18 Blend-(a) 25% C.sub.16 n- -- 58.3 5820 failed -2.165 clear.sup.4 paraffin and 25% C.sub.16 olefin, (chlorinated to 63.7 weight %); and (b) 25% C.sub.12 n-paraffin and 25% C.sub.12 .alpha.-olefin (chlorinated to 52.8 weight percent).sup.1 19 Blend-(a) 50% C.sub.16 -.alpha. -- 57.9 7200 failed -0.55 clear.sup.4 olefin (chlorinated to 57.8 weight percent); and (b) 50% C.sub.12 .alpha.-olefin (chlorinated to 57.9 weight percent).sup.1 20 UNICHLOR.RTM. 52.8 (50) 543 failed -13.40 not tested 50 L 50 (C.sub.10 -C.sub.13 paraffin).sup.1 21 UNICHLOR.RTM. 59.0 (60) 1750 failed -5.40 not tested 60 L 60 (C.sub.10 -C.sub.12 paraffin).sup.1 22 SANTICIZER.RTM.278 none none 663 failed not tested not tested (phthalate ester).sup.1 23 TOYOPARAX-145 44.8 Not available 179 failed -2.24 cloudy.sup.3 (paraffin).sup.1 24 TOYOPARAX-150 50.8 Not available 1227 failed -0.47 clear.sup.3 (paraffin).sup.1 25 CERECLOR S-52 50.8 Not available 1185 failed -0.49 clear.sup.3 (paraffin).sup.1 __________________________________________________________________________ .sup.1 Denotes comparison run outside the scope of this invention. .sup.2 "Failed" denotes failure during initial 24hour period. Figure in ( denotes number of days after which material passed fog test. .sup.3 Tested only at 1/1 ratio of polysulfide to chlorinated hydrocarbon .sup.4 Tested at 1/1, 3/1 and 1/3 ratios of polysulfide to chlorinated hydrocarbon. .sup.5 Data reported represents average of three determinations? .sup.6 Data reported represents average of four determinations.

Following the chlorination procedure used for most of the samples described above, several additional comparison samples, also outside the scope of the invention, were prepared. All these samples were prepared from feeds of a particularly high purity of over 96.0 mole percent with a maximum content of less than 1.0 mole percent of the next lower hydrocarbon with an even number of carbon atoms per molecule. The samples are described below in Table II as Runs 26-33.

TABLE II __________________________________________________________________________ ADDITIONAL CHLORINATED LIQUID HYDROCARBON SAMPLES Actual Weight (Estimaed Viscosity- Run Percent Chlor- Weight Percent Centipoises Fog.sup.2 Heat Loss-Weight Compati- No. Nature of Feed ine Content Chlorine Content at 25.degree. C. Test after 24 hours at 105.degree. C. bility __________________________________________________________________________ 26 C.sub.8 Normal Paraffin.sup.1 44.0 (45) 8.1 Failed -96.6 Clear.sup.4 27 C.sub.8 Normal Paraffin.sup.1 55.3 (55) 20 Failed -82.0 Clear.sup.4 28 C.sub.10 Normal Paraffin.sup.1 47.2 (45) 21 Failed -44.10 Clear.sup.4 29 C.sub.10 Normal paraffin.sup.1 54.4 (55) 134 Failed -14.98 Clear.sup.4 30 C.sub.12 Normal Paraffin.sup.1 43.9 (45) 40 Failed -13.00 Cloudy.sup.3,4 31 C.sub.12 Normal Paraffin.sup.1 54.2 (55) 679 Failed -1.70 Clear.sup.4 32 C.sub.14 Normal Paraffin.sup.1 45.4 (45) 157 Failed -1.86 Cloudy.sup.3,4 33 C.sub.14 Normal Paraffin.sup.1 54.2 (55) 3,824 Failed +0.09 Clear.sup.4 __________________________________________________________________________ .sup.1 Denotes comparison run outside the scope of this invention. .sup.2 Samples tested at about 77.degree. C. .sup.3 Solution visibly clouded.? .sup.4 Tested only at 1/1 ratio of polysulfide to chlorinated hydrocarbon

EXAMPLE II

Fog tests were performed on all the samples, the results of which are set forth in Tables I and II.

In these tests, a large test tube containing 75 grams of a sample plasticizer and 50 ml. of glass beads (for weighting purposes and level control) was prepared for each sample. The test tubes were corked with a stopper having an aperture in the center and a small test tube was placed snugly through the aperture. These small test tubes acted as an air-cooled cold finger type condenser, providing a surface on which any volatilized material might deposit. The double test tube arrangement was partially immersed in a hot oil bath kept at a temperature of from about 71.degree. C. to about 77.degree. C., such that the temperature of the upper tube was about 42.degree. C. to about 49.degree. C. The chlorinated hydrocarbons of the invention were all non-fogging after at least one day, with several being non-fogging after at least two, three or four days.

EXAMPLE III

Most of the samples were tested to determine heat loss values. Each sample was exposed to an elevated temperature of about 105.degree. C. for a period of about 24 hours. The results appear in Tables I and II.

As may be seen from these results, all of the chlorinated hydrocarbons within the scope of this invention are stable and non-volatile products which are not subject to significant heat loss, i.e., maintain a heat loss value of less than 0.5 weight percent in a period of about 24 hours.

EXAMPLE IV

The plasticizer samples of Runs 3 and 20-25 were incorporated into a polysulfide rubber sealant formulation and the performance of the sealant formulations incorporating each of the sample plasticizers was determined. Run 3 is within the scope of this invention and Runs 20-25 are for comparison purposes. The sealant composition and curing paste used to prepare the various sample formulations are described below:

______________________________________ Ingredient Parts by Weight ______________________________________ Sealant Composition THIOKOL.RTM. LP-2 Polysulfide polymer.sup.1 50 THIOKOL.RTM. LP-32 Polysulfide polymer.sup.2 50 Sample Chlorinated Liquid Hydrocarbon 25 Filler (Keystone White-Calcium Carbonate) 45 Pigment (titanium dioxide) 15 Retarding Agent (Stearic Acid) 0.2 Total 185.2 Curing Paste Plasticizer (SANTICIZER.RTM. 278-phthalate ester) 7.5 Catalyst (lead dioxide-PbO.sub.2) 7.5 Total 15.0 ______________________________________

The sealant composition and curing paste were compounded separately by mixing the necessary ingredients and subsequently subjecting the mixtures to several passes on a three-roll paint mill. The sealant composition and curing paste were then blended in the proportions shown until a uniform color was obtained. After blending, the sealant formulation was press-cured overnight at room temperature (about 25.degree. C.) in a standard ASTM cavity mold and subsequently aged for seven days.

After curing and aging, performance tests were carried out on the sealant formulations to determine the compatibility of the sample plasticizers with the polysulfide rubber and the stability of the formulations.

To determine the stability of the cured polysulfide rubber sealant formulation, the formulation was subjected to an elevated temperature of about 70.degree. C. for a period of about 24 hours. Weight loss measurements were taken, and are reported in Table III:

TABLE III __________________________________________________________________________ Weight Loss Measurements in Cured Formulations (Estimated Weight Actual Weight Per- Percent Chlorine Weight % Loss of Run No. Nature of Feed cent Chlorine Content Content Plasticizer.sup.1,2 __________________________________________________________________________ 3 C.sub.15 normal paraffin 53.8.sup.4 -2.83 20 UNICHLOR.RTM. 50 L 50 52.8 (50) -7.35 (C.sub.10 -C.sub.13 paraffin).sup.3 21 UNCHLOR.RTM.60 L 60 59.0 (60) -5.35 (C.sub.10 -C.sub.12 paraffin).sup.3 22 SANTICIZER.RTM. 278 0.0 (0) -4.34 (phthalate ester).sup.3 23 TOYOPARAX-145 44.8 Not available -5.06 (paraffin).sup.3 24 TOYOPARAX-150 50.8 Not available -3.49 (paraffin).sup.3 25 CERECLOR S-52 50.8 Not available -3.90 (paraffin).sup.3 __________________________________________________________________________ .sup.1 Based on total weight of plasticizer and sealant formulation. .sup.2 Performed in accordance with ASTM Test Designation D 120367.? .sup.3 Denotes comparison run outside the scope of this invention. .sup.4 Denotes average of four determinations.

As can be seen from this data, the polysulfide rubber formulations of this invention, namely Run No. 3, was satisfactory and showed excellent stability, with less than 5.0 weight percent loss.

EXAMPLE V

The cured formulations of Runs 3 and 20-25 were stored for one week at a constant temperature of about 27.degree. C. and 50% relative humidity and were subjected to additional physical property tests.

It may be seen from this data that Run No. 3 within the scope of the invention, when compared, e.g., to the commercially acceptable plasticizer of Run 22 performs effectively, as shown in Table IV.

TABLE IV ______________________________________ ADDITIONAL PHYSICAL PROPERTIES OF THE CURED SEALANT FORMULATIONS Tensile 300% Strength Run Modulus.sup.1 Max.sup.1 Elongation.sup.1 Hardness No..sup.3 (PSI) (PSI) % Shore.sup.2 ______________________________________ 3 77 90.0 420 26.0 20 .sup.4 94.0 270 27.0 21 113 118.0 340 31.0 22 97.9 114.0 485 27.0 23 52 78.0 315 25.0 24 -- 79.0 285 27.0 25 82 89.0 355 26.0 ______________________________________ .sup.1 Test performed in accordance with ASTM Test Designation D412-68, herein incorporated by reference. .sup.2 Test performed in accordance with ASTM Test Designation D2240-75, herein incorporated by reference. A Shore A2 durometer was used. .sup.3 For details of Runs, See Table I. .sup.4 Failed before reaching 300% modulus

EXAMPLE VI

To determine the compatibility of the sample chlorinated hydrocarbons in "green" or uncured polysulfide rubber, equal volume parts of the chlorinated hydrocarbons of Runs No. 1-19 and 23-33 and THIOKOL.RTM. LP-2 rubber were mixed in solution and maintained at room temperature (about 25.degree. C.) for about 18 hours and the following results were obtained. A "clear" solution would be indicative of a high or acceptable level of compatibility. A "cloudy" solution is one which is visibly clouded and represents an unacceptable level of compatibility. Those solutions which were "incompatible" were separated into two visibly distant layers. The results of the "green" compatibility test are set forth in Tables I and II above.

As may be seen from Tables I and II, for the paraffins having a low number of carbon atoms per molecule, e.g., C.sub.8 -C.sub.10 paraffins, a 45 weight percent chlorine content appears sufficient to provide the necessary compatibility, but these all have a volatility which is extremely high and which would result in extensive fogging. As the number of carbon atoms increases to, e.g., 12 or 14, the 45 weight percent chlorine content becomes insufficient to provide the compatible formulation, the volatility is again so high as to result in fogging. The improved chlorinated hydrocarbons of the invention, on the other hand, exhibit excellent compatibility without suffering from undesirable fogging.

Thus, the improved chlorinated hydrocarbons of the invention combine a high compatibility of polysulfide rubber sealant compositions with a volatility low enough to avoid fogging and a viscosity low enough to provide ease in handling to produce a plasticizer which is subject to very low heat loss and which results in a stable polysulfide rubber sealant formulation when blended therein.

Although the invention has been described with preferred embodiments, it is to be understood that variations and modifications may be resorted to as will be apparent to those skilled in the art. Such variations and modifications are considered to be within the purview and the scope of the claims appended hereto.

Claims

1. An improved polysulfide rubber sealant formulation comprising

a liquid polysulfide polymer; and

a chlorinated hydrocarbon plasticizer in an amount effective to plasticize said polysulfide polymer and consisting essentially of a chlorinated hydrocarbon selected from chlorinated paraffins containing from 14 to about 15 carbon atoms per molecule, chlorinated alpha-olefins containing from 14 to about 15 carbon atoms per molecule, and blends thereof; the chlorine content of the chlorinated hydrocarbon ranging from 50 to 59 weight percent; the chlorinated hydrocarbon plasticizer having a combination of (a) number of carbon atoms per molecule and (b) chlorine content sufficient to provide a non-fogging and compatible plasticizer in a polysulfide rubber sealant formulation; the chlorinated hydrocarbon plasticizer having a viscosity of less than about 25,000 centipoises at 25.degree. C. and having a heat loss value of less than about 0.5 weight percent;

and the polysulfide rubber sealant formulation being stable when cured.

2. The improved polysulfide rubber sealant formulation of claim 1 wherein the chlorinated hydrocarbon is a chlorinated paraffin containing 15 carbon atoms per molecule; the chlorine content of the chlorinated paraffin ranging from 52 to 56 weight percent; wherein the chlorinated hydrocarbon plasticizer has a viscosity of less than about 15,000 centipoises at 25.degree. C.; and wherein the liquid polysulfide polymer is thiol-terminated.

3. The improved polysulfide rubber sealant formulation of claim 2 wherein the chlorinated hydrocarbon plasticizer has a viscosity of less than about 10,000 centipoises at 25.degree. C.

4. An improved polysulfide rubber sealant formulation comprising

a liquid polysulfide polymer;

a chlorinated hydrocarbon plasticizer in an amount effective to plasticize said polysulfide polymer and selected from chlorinated paraffins containing from 14 to about 15 carbon atoms per molecule and chlorinated alpha-olefins containing from 14 to about 15 carbon atoms per molecule and blends thereof; the chlorine content of the chlorinated hydrocarbon ranging from 50 to 59 weight percent; the chlorinated hydrocarbon plasticizer having a viscosity of less than about 25,000 centipoises at 25.degree. C., a heat loss value of less than about 0.5 weight percent and a combination of (a) number of carbon atoms per molecule and (b) chlorine content sufficient to provide a non-fogging and compatible plasticizer in a polysulfide rubber sealant formulation;

a pigment;

a retarding agent; and

a filler;

the polysulfide rubber sealant formulation being stable when cured, the curing being effected by the incorporation of an effective amount of curing agent.

5. The improved polysulfide rubber sealant formulation of claim 4 wherein the formulation comprises about 100 parts by weight of a thiol-terminated polysulfide polymer;

from about 10 to 100 parts by weight of a chlorinated hydrocarbon plasticizer consisting essentially of a chlorinated paraffin containing 15 carbon atoms per molecule; the chlorine content of the chlorinated paraffin ranging from 52 to 56 weight percent; the chlorinated hydrocarbon plasticizer having a viscosity of less than about 15,000 centipoises at 25.degree. C.;

from about 0.1 to about 40 parts by weight of a pigment;

from about 0.01 to about 1.0 parts by weight of a retarding agent; and

from about 25 to about 150 parts by weight of a filler; and wherein the curing is effected by the incorporation of from about 5 to about 12 parts by weight of a curing agent.

6. The improved polysulfide rubber sealant formulation of claim 5 wherein the formulation comprises

from about 20 to about 75 parts by weight of said chlorinated hydrocarbon plasticizer;

from about 0.1 to about 20 parts by weight of a pigment;

from about 0.01 to about 0.5 parts by weight of a stearic acid retarding agent; and

from about 50 to about 100 parts by weight of a filler;

wherein the chlorinated hydrocarbon plasticizer has a viscosity of less than 10,000 centipoises at 25.degree. C.; and wherein the curing is effected by the incorporation of from about 7 to about 10 parts by weight of curing agent and an equal amount of a carrier.

7. A method for preparing an improved polysulfide rubber sealant formulation comprising mixing together the liquid polysulfide polymer and chlorinated hydrocarbon plasticizer of claim 1.

8. A method for preparing an improved polysulfide rubber sealant formulation comprising mixing together the liquid polysulfide polymer and the chlorinated hydrocarbon plasticizer of claim 2.

9. A method for preparing an improved polysulfide rubber sealant formulation comprising mixing together the liquid polysulfide polymer and the chlorinated hydrocarbon plasticizer of claim 3.

10. A method for preparing the improved polysulfide rubber sealant formulation of claim 4 comprising chlorinating a hydrocarbon selected from paraffins containing from 14 to about 15 carbon atoms per molecule and alpha-olefins containing from 14 to about 15 carbon atoms per molecule or blends thereof to a chlorine content ranging from 50 to 59 weight percent; mixing the chlorinated hydrocarbon together with a liquid polysulfide polymer, a pigment, a retarding agent and a filler to form a polysulfide rubber sealant formulation and curing the polysulfide rubber sealant formulation by incorporating an effective amount of a curing agent.

11. A method for preparing the improved polysulfide rubber sealant formulation of claim 5 comprising chlorinating a hydrocarbon consisting essentially of a paraffin containing 15 carbon atoms per molecule to a chlorine content ranging from 52 to 56 weight percent; mixing from about 10 to about 100 parts by weight of the chlorinated paraffin together with about 100 parts by weight of a liquid polysulfide polymer, from about 25 to about 100 parts by weight of a filler, from about 0.01 to about 1.0 parts by weight of a retarding agent and from about 0.1 to about 40 parts by weight of a pigment to form a polysulfide rubber sealant formulation; and curing the polysulfide rubber sealant formulation by incorporating from about 5 to about 12 parts by weight of a curing agent.

12. A method for preparing the improved polysulfide rubber sealant formulation of claim 6 comprising chlorinating a hydrocarbon consisting essentially of a paraffin containing 15 carbon atoms per molecule to a chlorine content ranging from 52 to 56 weight percent; mixing from about 20 to about 75 parts by weight of the chlorinated paraffin together with about 100 parts by weight of a liquid polysulfide polymer, from about 50 to about 100 parts by weight of a filler, from about 0.01 to about 0.5 parts by weight of a stearic acid retarding agent and from about 0.1 to about 20 parts by weight of a pigment to form a polysulfide rubber sealant formulation; and curing the polysulfide rubber sealant formulation by incorporating from about 7 to about 10 parts by weight of a curing agent and an equal amount of a carrier.

13. An improved polysulfide rubber sealant formulation comprising

a liquid polysulfide polymer; and

a chlorinated hydrocarbon plasticizer in an amount effective to plasticize said polysulfide polymer and consisting essentially of a chlorinated hydrocarbon selected from chlorinated paraffins containing from 14 to 22 carbon atoms per molecule, chlorinated alpha-olefins containing from 14 to 22 carbon atoms per molecule, and blends thereof; the chlorine content of the chlorinated hydrocarbon ranging from 50 to about 51 weight percent; the chlorinated hydrocarbon plasticizer having a combination of (a) number of carbon atoms per molecule and (b) chlorine content sufficient to provide a non-fogging and compatible plasticizer in a polysulfide rubber sealant formulation; the chlorinated hydrocarbon plasticizer having a viscosity of less than about 25,000 centipoises at 25.degree. C. and a heat loss value of less than about 0.5 weight percent; and the polysulfide rubber sealant formulation being stable when cured.

14. An improved polysulfide rubber sealant formulation comprising

a liquid polysulfide polymer;

a chlorinated hydrocarbon plasticizer in an amount effective to plasticize said polysulfide polymer and consisting essentially of a chlorinated hydrocarbon selected from chlorinated paraffins containing from 14 to 22 carbon atoms per molecule, chlorinated alpha-olefins containing from 14 to 22 carbon atoms per molecule, and blends thereof; the chlorine content of the chlorinated hydrocarbon ranging from 50 to about 51 weight percent; the chlorinated hydrocarbon plasticizer having a viscosity of less than about 25,000 centipoises at 25.degree. C., a heat loss value of less than about 0.5 weight percent and a combination of (a) number of carbon atoms per molecule and (b) chlorine content sufficient to provide a non-fogging and compatible plasticizer in a polysulfide rubber sealant formulation;

a pigment;

a retarding agent; and

a filler;

the polysulfide rubber sealant formulation being stable when cured, the curing being effected by the incorporation of an effective amount of a curing agent.

15. The improved polysulfide rubber sealant formulation of claim 14 wherein the formulation comprises

100 parts by weight of a thiol-terminated polysulfide polymer;

from about 10 to about 100 parts by weight of a chlorinated hydrocarbon plasticizer selected from chlorinated paraffins containing from 14 to 22 carbon atoms per molecule, chlorinated alpha-olefins containing from 14 to 22 carbon atoms per molecule, and blends thereof; the chlorinated hydrocarbon plasticizer having a viscosity of less than about 15,000 centipoises at 25.degree. C.;

from about 0.1 to about 40 parts by weight of a pigment;

from about 0.01 to about 1.0 parts by weight of a retarding agent; and

from about 25 to about 50 parts by weight of a filler; and wherein the curing is effected by the incorporation of from about 5 to about 12 parts by weight of a curing agent.

16. The improved polysulfide rubber sealant formulation of claim 15 wherein the formulation comprises from about 20 to about 75 parts by weight of said chlorinated hydrocarbon plasticizer; from about 0.1 to about 20 parts by weight of a pigment;

from about 0.01 to a about 0.5 parts by weight of a stearic acid retarding agent; and

from about 50 to about 100 parts by weight of a filler; wherein the chlorinated hydrocarbon plasticizer has a viscosity of less than about 10,000 centipoises at 25.degree. C.; and wherein the curing is effected by the incorporation of from about 7 to about 10 parts by weight of a curing agent and an equal amount of a carrier.

17. A method for preparing an improved polysulfide rubber sealant formulation comprising mixing together the liquid polysulfide polymer and chlorinated hydrocarbon plasticizer of claim 13.

18. A method for preparing the improved polysulfide rubber sealant formulation of claim 14 comprising chlorinating a hydrocarbon selected from paraffins containing from 14 to 22 carbon atoms per molecule, alpha-olefins containing from 14 to 22 carbon atoms per molecule, and blends thereof to a chlorine content ranging from 50 to about 51 weight percent; mixing the chlorinated hydrocarbon together with a liquid polysulfide polymer, a pigment, a retarding agent and a filler to form a polysulfide rubber sealant formulation; and curing the polysulfide rubber sealant formulation by incorporating an effective amount of a curing agent.

19. A method for preparing the improved polysulfide rubber sealant formulation of claim 15 comprising chlorinating a hydrocarbon selected from paraffins containing from 14 to 22 carbon atoms per molecule, alpha-olefins containing from 14 to 22 carbon atoms per molecule, and blends thereof to a chlorine content ranging from 50 to about 51 weight percent; mixing from about 10 to about 100 parts by weight of the chlorinated hydrocarbon together with about 100 parts by weight of a liquid polysulfide polymer, from about 25 to about 150 parts by weight of a filler, from about 0.01 to about 1.0 parts by weight of a retarding agent and from about 0.1 to about 40 parts by weight of a pigment to form a polysulfide rubber sealant formulation; and curing the polysulfide rubber sealant formulation by incorporating from about 5 to about 12 parts by weight of a curing agent.

20. A method for preparing the improved polysulfide rubber sealant formulation of claim 16 comprising chorinating a hydrocarbon selected from the paraffins containing from 14 to 22 carbon atoms per molecule, alpha-olefins containing from 14 to 22 carbon atoms per molecule, and blends thereof to a chlorine content ranging from 50 to about 51 weight percent; mixing from about 20 to about 75 parts by weight of the chlorinated hydrocarbon together with about 100 parts by weight of a liquid polysulfide polymer, from about 50 to about 100 parts by weight of a filler, from about 0.01 to about 0.5 parts by weight of a stearic acid retarding agent and from about 0.1 to about 20 parts by weight of a pigment to form a polysulfide rubber sealant formulation; and curing the polysulfide rubber sealant formulation by incorporating from about 7 to about 10 parts by weight of a curing agent and an equal amount of a carrier.

21. An improved polysulfide rubber sealant formulation comprising a liquid polysulfide polymer and a chlorinated hydrocarbon plasticizer consisting essentially of a blend of chlorinated hydrocarbons selected from (a) chlorinated paraffins containing from 14 to about 15 carbon atoms per molecule, chlorinated alpha-olefins containing from 14 to about 15 carbon atoms per molecule, and blends thereof; and (b) chlorinated paraffins containing from about 21 to 22 carbon atoms per molecule, chlorinated alpha-olefins containing from about 21 to 22 carbon atoms per molecule and blends thereof; the chlorine content of the improved chlorinated hydrocarbon ranging from 50 to 59 weight percent; the chlorinated hydrocarbon plasticizer having a combination of (c) number of carbon atoms per molecule and (d) chlorine content sufficient to provide a non-fogging and compatible plasticizer in a polysulfide rubber sealant formulation; the chlorinated hydrocarbon plasticizer having a viscosity of less than about 25,000 centipoises at 25.degree. C. and a heat loss value of less than about 0.5 weight percent; the chlorinated hydrocarbon plasticizer being present in an amount effective to plasticize said polysulfide polymer; the polysulfide rubber sealant formulation being stable when cured.

22. An improved polysulfide rubber sealant formulation comprising a liquid polysulfide polymer; a chlorinated hydrocarbon plasticizer consisting essentially of a blend of chlorinated hydrocarbons selected from (a) chlorinated paraffins containing from 14 to about 15 carbon atoms per molecule, chlorinated alpha-olefins containing from 14 to about 15 carbon atoms per molecule, and blends thereof; and (b) chlorinated paraffins containing from about 21 to 22 carbon atoms per molecule, chlorinated alpha-olefins containing from about 21 to 22 carbon atoms per molecule and blends thereof; the chlorine content of the improved chlorinated hydrocarbon ranging from 50 to 59 weight percent; the chlorinated hydrocarbon plasticizer having a combination of (c) number of carbon atoms per molecule and (d) chlorine content sufficient to provide a non-fogging and compatible plasticizer in a polysulfide rubber sealant formulation; the chlorinated hydrocarbon plasticizer having a viscosity of less than about 25,000 centipoises at 25.degree. C. and a heat loss value of less than about 0.5 weight percent; the chlorinated hydrocarbon plasticizer being present in an amount effective to plasticize said polysulfide polymer; a pigment; a retarding agent; and a filler; the polysulfide rubber sealant formulation being stable when cured, the curing being effected by incorporation of an effective amount of curing agent.

23. A method for preparing an improved polysulfide rubber sealant formulation comprising mixing together a liquid polysulfide polymer and a chlorinated hydrocarbon plasticizer consisting essentially of a blend of chlorinated hydrocarbons selected from (a) chlorinated paraffins containing from 14 to about 15 carbon atoms per molecule, chlorinated alpha-olefins containing from 14 to about 15 carbon atoms per molecule, and blends thereof; and (b) chlorinated paraffins containing from about 21 to 22 carbon atoms per molecule, chlorinated alpha-olefins containing from about 21 to 22 carbon atoms per molecule and blends thereof; the chlorine content of the improved chlorinated hydrocarbon ranging from 50 to 59 weight percent; the chlorinated hydrocarbon plasticizer having a combination of (c) number of carbon atoms per molecule and (d) chlorine content sufficient to provide a non-fogging and compatible plasticizer in a polysulfide rubber sealant formulation; the chlorinated hydrocarbon plasticizer having a viscosity of less than about 25,000 centipoises at 25.degree. C. and a heat loss value of less than about 0.5 weight percent.

24. A method for preparing the improved polysulfide rubber sealant formulation comprising a liquid polysulfide polymer; a chlorinated hydrocarbon plasticizer consisting essentially of a blend of chlorinated hydrocarbons selected from (a) chlorinated paraffins containing from 14 to about 15 carbon atoms per molecule, chlorinated alpha-olefins containing from 14 to about 15 carbon atoms per molecule, and blends thereof; and (b) chlorinated paraffins containing from about 21 to 22 carbon atoms per molecule, chlorinated alpha-olefins containing from about 21 to 22 carbon atoms per molecule and blends thereof; the chlorine content of the improved chlorinated hydrocarbon ranging from 50 to 59 weight percent; the chlorinated hydrocarbon plasticizer having a combination of (c) number of carbon atoms per molecule and (d) chlorine content sufficient to provide a non-fogging and compatible plasticizer in a polysulfide rubber sealant formulation; the chlorinated hydrocarbon plasticizer having a viscosity of less than about 25,000 centipoises at 25.degree. C. and a heat loss value of less than about 0.5 weight percent, the chlorinated hydrocarbon plasticizer being present in an amount effective to plasticize said polysulfide polymer; a pigment; a retarding agent; and a filler; the polysulfide rubber sealant formulation being stable when cured, the curing being effected by incorporation of an effective amount of curing agent, comprising chlorinating a composition consisting essentially of a blend of hydrocarbons selected from (a) paraffins containing from 14 to about 15 carbon atoms per molecule, alpha-olefins containing from 14 to about 15 carbon atoms, and blends thereof; and (b) paraffins containing from about 21 to 22 carbons per molecule, alpha-olefins containing from about 21 to 22 carbon atoms per molecule, and blends thereof to a chlorine content ranging from 50 to 59 weight percent; mixing the chlorinated hydrocarbons together with a liquid polysulfide polymer, a pigment, a retarding agent and a filler to form a polysulfide rubber sealant formulation; and curing the polysulfide rubber sealant formulation by incorporating an effective amount of a curing agent.